基于随机瓦片的地图生成，如团结中的Terraria

我想用Unity和C从游戏Terraria和Starbound中的瓦片生成一个地图#到目前为止，我所做的一切都不起作用，我不知道为什么。。。有什么帮助/想法/建议吗？

using UnityEngine;
using System.Collections;
public class MapGeneration : MonoBehaviour {
public int mapWidth, mapHeight, spreadDegree;
GameObject[,] blocks;
public GameObject baseBlock;
public int maxHeightAllowed;
public int nullDispersion;
int dispersionZone;
void Start() {
    GenerateMap();
}
void GenerateMap() {
    dispersionZone = maxHeightAllowed - nullDispersion;
    blocks = new GameObject[mapWidth, mapHeight];
    for(int x = 0; x < blocks.GetLength(0); x++) {
            for(int y = nullDispersion; y <= maxHeightAllowed; y++) {
                int heightDiff = y - nullDispersion;
                float dispersionModifier = Mathf.Sin( (heightDiff / dispersionZone) * 90);
                float random = Random.Range(0, 1);
                if(random > dispersionModifier) {
                    blocks[x,y] = (GameObject)Instantiate(baseBlock, new Vector2(x, y), Quaternion.identity);
                } else if (y < blocks.GetLength(1) && blocks[x,y+1] != null) {
                    blocks[x,y] = (GameObject)Instantiate(baseBlock, new Vector2(x, y), Quaternion.identity);
                }
            }
            for(int y = 0; y < nullDispersion; y++) {
                blocks[x,y] = (GameObject)Instantiate(baseBlock, new Vector2(x, y), Quaternion.identity);
            }
    }
}
}

(heightDiff / dispersionZone)

* 90

            if(random > dispersionModifier) {
                blocks[x,y] = (GameObject)Instantiate(baseBlock, new Vector2(x, y), Quaternion.identity);
            } else if (y < blocks.GetLength(1) && blocks[x,y+1] != null) {
                blocks[x,y] = (GameObject)Instantiate(baseBlock, new Vector2(x, y), Quaternion.identity);
            }